/Engine/Plugins/Experimental/LandscapePatch/Source/LandscapePatch/Public/LandscapeTexturePatch.h
Gives size in unscaled world coordinates of the patch in the world, based off of UnscaledCoverage and texture resolution (i.e., adds a half-pixel around UnscaledCoverage).
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintCallable, Category=LandscapePatch) virtual FVector2D GetFullUnscaledWorldSize() const